HP Fortran Programmer's Guide (March 2010)

Compiling and linking
Compiling with the f90 command
Chapter 2 71
+O[no]info
+Oinfo causes the compiler to display informational messages about the
optimization process. The +Oinfo option provides feedback that can help
you to determine whether the compiler optimized time-critical sections of
your program. It can be used at any level of optimization but is most useful
at level 3.
Currently, this option provides feedback for the following optimizations:
• Cloning, the replacement of a call to a routine by a call to a clone, which
is a copy of the routine with changes specific to that call site.
• Inlining.
• Loop transformations to improve cache performance.
• Vectorization.
The default, +Onoinfo, disables the display of informational messages about
optimization.
+O[no]initcheck
The initialization checking feature of the optimizer has three possible
states: on, off, or unspecified. When this option is specified in the on state
(+Oinitcheck), the optimizer initializes to zero any local, nonarray,
nonstatic variables that are uninitialized with respect to at least one path
leading to a use of the variable.
When +Onoinitcheck is specified, the optimizer issues warning messages
when it discovers definitely uninitialized variables, but does not initialize
them.
When this option is unspecified, the optimizer initializes to zero any local,
scalar, nonstatic variables that are definitely uninitialized with respect to
all paths leading to a use of the variable.
This option is only effective at optimization level 2 or higher.
+O[no]inline
+Oinline makes all subprograms eligible for inlining. This option is only
effective at optimization level 3 or higher.
The +Onoinline option disables inlining for all subprograms in your
program.
The default is +Oinline at optimization level 3 and +Onoinline at the
lower levels.